Thought I would update my post in case someone else comes looking with a similar problems.
Firstly I now think the catnap problem is not a problem as such, I thought about how much sleep she had had during the day and on both days she dropped catnap she had 2 naps of min1.5hrs-1.75hrs where as previously she would only take 1-1hr15Min's in the morning and 1.5hrs in afternoon, so I guess she had just got all the daytime sleep she needed. In future when this happens I will just move the bedtime routine right down to when she should be going down for catnap and this seems to work, she even took a full feed 45Min's earlier than normal, in fact now I have dropped dream feed all her feeds have improved hugely.
Secondly with regard to bedtime separation anxiety. What I have successfully done for last 2 nights is take her into her room and sit with her cradled in my arms and sing her lullaby over and over until she starts to turn her head into my body and arch her back, then continuing with lullably (theme from Winnie the pooh) I put her down in cot and finish lullaby, then I say night nights now my darling, mummy is right here. after just a few squeaks she tries to go to sleep, sometimes successfully other times not, it frustrates her when sleep doesn't just happen so she gets a little more agitated but at no point did she really cry, if she gets to fussy I say 'its OK only night nights, mummy is here' this seems to calm her into having another go at sleep. Either way she kept on looking up to see if I was still there, even when she had dropped of she would wake 10Min's later and look at me, then settle back down. The first night took a little over an hour before she gave up and settled fully of to sleep, last night she was more fussy but she still managed to go off in just under an hour. I'm hoping as she gets used to mummy still being there she will feel more confident and need to check less and less until hopefully she will once again be secure enough to just go of to sleep without me being there.
I think why I didn't try this technique at first and got a little lost is because it can really through you of course when they suddenly stop doing something they had been doing so well before. I also think that in this situation PU/PD, which I swear by, was actually making things worse, because she wanted me to pick her up so calmed as soon as I did, but then was getting very annoyed at being put back down straight away. It was as if she was learning that to stay in my arms she had to just keep crying and in this wound up overtired state sleep was nearly impossible until she had burnt herself right out and passed out.
I will update again soon with how its all working out.